1. Field of the Invention
The invention relates to the field of cooling technology and can be applied to the circuit construction of cooling plants which includes a plurality of cooling cells operating in parallel.
2. Description of the Prior Art
In large-scale technical plants, cooling plants are used for the removal of excess process heat, these include a primary and a secondary coolant loop, both cooling loops being coupled through a heat exchanger. In the secondary cooling loop, cooling towers are used for transferring the heat to the environment. The cooling water therein trickles or drips down and is brought into contact with the atmospheric air. In this connection, a distinction must be drawn between naturally ventilated and artificially ventilated cooling towers. The artificially ventilated cooling towers are equipped with at least one blower which draws or pushes the air through the cooling tower (see, for example, the DIN Publication of 1947, Issued June 1959, entitled "Performance Tests on Cooling Towers"; and the journal "Waerme", Volume 79, No. 1, Pages 5 to 9).
Artificially ventilated cooling towers (blower cooling towers) of small construction are frequently provided in larger numbers and operate in parallel in order to obtain a high cooling capacity. These cooling towers, also called "Cooling Cells", always include, in addition to a motor-driven blower, a cooling water pump which precedes the spraying device for the warm water entering the cooling cell. The cold water leaving the cooling cell is fed to a common cold water collecting basin from which it is fed to the heat exchanger by means of a pump (secondary cooling water pump). The warmed cooling water can first be collected in a warm water basin and travels from there to the cooling cells by means of appropriate pumps (see the brochure "Wet Cooling Towers" of the firm Balcke-Durr, No. 2000-3/76). To adapt the cooling plants, constructed from several cooling cells provided for operation in parallel, to different cooling loops, as well as to operating and/or weather conditions, electrically controlled hydraulic circuits are required which are essentially characterized by the use of controlled valves and expensive control circuits. This engenders a certain degree of being trouble prone to the entire cooling plant.